Tiller



G. PENEFF Nov. 25, 1930.

TILLER Filed Sept. 20, 1928 5 Sheets-Sheet l G. PENE FF Nov. 25, 1930.

TILLER Filed Sept. 20, 1928 5 Sheets-Sheet 2 G. PENEFF Nov. 25, 1930.

TILLER Filed Sept. 20, 1928 5 Sheets-Sheet 3 UT H G. PENEFF Nov. 25; 1930 TILLER Filed Sept. 20, 1928 5 Sheets-:Sheet 4 G. PENEFF Nov.' 25, 1930.

TILLER 5 Sheets-Sheet 5 Filed Sept. 20, 1928 Patented Nov. 25, 1930 UNITED STATES PATENT OFFICE GEORG PENEEF, OF BERLIN-WILMERSDORF, GERMANY, ASSIGNOR '10 SIEMENS- SGHUCKEBTWEBKE AKTIENGESELLSCHAFT, OI BERLIN-SIEMENSSTADT, GERMANY,

A CORPORATION 01? GERMANY TILLER Application filed September 20, 1928, Serial No. 307,141, and in Germany August 15, 1927.

I have filed application in Germany Aug. 15. 1927 and Sept. 8, 1927.

My invention relates to improvements in tillers, and more specifically to tillers or cultivators with rotary tools, which penetrate into the soil, breakup the surface of the ground and crumple the soil. Such tillers are usually fitted with a motor drive, which propels the implement and simultaneously rotates the tool which is mounted on a com- 1 mon rotary member.

This kind of tiller consists usually of steel hooks, which are connected with the driven rotary member of the implement by means of coiled or helical springs with a plurality of turns.

The object of my invention is a spring support for the tiller of such character that these supporting springs are strained to the same 29 extent in all their cross-sections or along their entire length. Such a uniformit of stress greatly extends the life of these springs.

A further object of my invention is to reduce the diameter of those parts, which do not directly serve for cultivating the ground,

i. e. the diameter of the entire spring arrangement, in relation to the diameter of the circle described by the points of the tools during their rotation. In the known machines with coiled springs the coils of the springs of necessity have a comparatively large diameter and are thus liable to touch or even penetrate into the ground and to become clogged with dirt and roots which impairs their resiliency. and necessitates frequent cleaning of the machine. Moreover, this drag of the springs considerably increases the required propelling power.

All of these disadvantages are overcome by employing according to my invention torsion springs instead of the usual coiled springs.

Various embodiments of my invention are illustrated in the accompanying drawings,

in which Fig. 1 shows a general outside view of a power driven rotary tiller;

Fig. 2 shows in larger scale and partly in 59 longitudinal section the detail construction of the resilient tiller arrangement on line 22 in Fig. 1;

Fig. 3 shows in detail the location of spring 3 in its right hand end socket, seen in plan view on the section line 33 in Fig. 2;

Fig. 4 shows a rear end view of the tiller hub portion 10 in Fig. 2, one of the plates (9) being removed;

Fig. 5 shows a transverse section of the hub portion on line 55 in Fig. 4;

Fig. 6 shows in section a modification of the torsionspring lock and of the attachment of the tiller hook thereto, which might be used in the modifications Fig. 7-9;

Fig. 7 shows a further modificationof the resilient tiller support in a view similar to Fig. 2;

Fig. 8 shows in larger scale partly in section the pivotal attachment of the torsion spring and a tiller hook to the supporting discs 19 in Fig. 7;

. Fig. 9 shows a partly sectional view of Fig. 8 on the line 9-9 in Fig. 8;

Fig. 10 shows a still further modification of Fig. 2, characterized by the mounting of the tiller hooks on yieldingly journalled tubes;

Figs. 11 to 14 show a group of further modifications of yieldingly mounted tiller hooks in which the individual tiller hooks are pivotally disposed on an axis spaced apart from the axis in which the torsion spring is located, Fig. 11 showing the geometrical spring axis in parallel to the tiller shaft, Fig. 12 showing the spring axis at right angles to the shaft axis, Fig. 13 showing a modification of Fig. 12, and Fig. 14 showing partly in section on the line 1414 in Fig. 13, and v Fig. 15 shows in a View, similar to Fig. 10 the general idea of tiller support and protection according to Figs. 11 to 14 in which however the torsion spring bars are encased in tubes the same as in Fig. 10.

Referring to Fig. 1, A is the body or frame portion of the implement, B contains the riving motor and C is the so-called tail which contains the tiller mounted on its shaft 1, the tiller hooks being shown at 8. The tiller is covered by a hood F, which prevents the throwing up of the soil. The implement is steered by means of the handlebars J and may by their aid be moved around the main wheel axle G, so that the working tools 8 may penetrate more or less into the soil as de- 811011. The motor (hives the runner wheels tion.

Referring to Fi s. 2-5, 1 is the tiller shaft on which is fixe a supportin disc 2. A torsion spring bar 3 is provi ed for each tiller hook 8, these bars being disposed in a circle around shaft 1 and being inserted with their looped ends into recesses 4 provided in disc 2 in which recesses they are secured by pins 5, as shown in Figs. 2 and 3, the latter being a horizontal section on the line 3-3, Fig. 2. A cover 6, consisting of a flanged disc placed on the hub of disc 2 and held in position by the nut 7, prevents the pins 5 from dropping out of their recesses. The springs 3 consist in this embodiment of two parts, which are con led with each other by a lock shown in detail in the Figs. 4 and 5, and serve at the same time for holding the particular tiller hook 8 which is carried by that spring in position. This coupling consists of two plates 9 and 10 held together by bolts 11, which also pass through the looped ends of springs 3 which latter are thereby clamped and joined together, to form in effect one torsion bar Between these plates is also clamped the tiller hook 8. The left hand end of each bar 3 is rotatably disposed in a supportin disc 12 which is located at the other end of t e tiller shaft, each bar being provided with a retaining collar 13. Disc 12 is fixed upon the tiller shaft and is enclosed by a cover 15 held in place upon the hub of the disc 12 by a nut 14. The spring bars in the modificatlon illustrated are of circular cross-section.

If the springs have rectangular, more particularly square cross-section, their attachment to the tool may be designed as shown in Fi 6 of the drawings. In this construction t e lock for carrying an individual hook 8 is designed as rotary element 16 similar for instance to the element 21 Figs. 7, 8 and 9 to be described later. In Figure 6 is the square torsion spring, 8 the tool and 12 a supporting disc which may be the equivalent of disc 19 in Figs. 8 and 9. Rotary elements 16 has a radial tapering s uare hole for the reception of the tool 8 an an axial square hole for the reception of the end of the spring 3. The spring and the tool 8 are secured in position by cotter pms 17 and 18.

Another form of resilient tiller is illllfh ll'lllll 111 the Figs. 7 t0 0n the tiller shaft 1 are mounted in this case a number of pairs of discs 19 each of which is provided with transverse holes 20 arranged in several concentric circles (see Fig. 9). Between each pair of discs is journalled a rotary element 21 1n which the tool 8 is fixed by means of a pin 22. Each element 21 is provided with a recess 23 at the side into which fits the bent over end of one of the torsion springs 3, as more clearly shown in Fig. 8. To each end of the shaft 1 is fixed a retainingdisc 32 provided with circumferential notches 133 receiving the bentover end of some of the bars 3, the disc being covered by an end cap 33 held in place by a out 134 similar to the manner shown at the right hand side of Fig. 2. By these means one end of the spring bars 3 is anchored the other end being fixed to the tiller hooks 8 as described. The cover 33 may be turned into such a position that its holes 39 register with the-milled recesses 133 of the disc 32, so that all springs may be simultaneously introduced or withdrawn through the holes 39. By turning the cover through half the pitch of the holes 39 all .the springs are simultaneously locked in place. Onthe inner face of cover 33 are pr0- vided two set pins 29 displaced by half the pitch of the holes and engaging correspondlng holes in the disc 32, so as to lock cover 33 in the two positions referred to above, i. e. for withdrawing or insertin the springs, or for locking the springs in pTace.

The bearing discs 19 have in this design as many concentrically arranged holes 20 as there are bars or torsion springs. The springs leading from the rotary elements 21 to their abutments pass through the holes of the intermediate bearing discs for some 01 the other tiller books 8. In this way the springs are supported by the discs and protected against bending strains. The discs 19 with their concentric holes may be produced by casting. Apart from the central opening for the tiller shaft only the precast bearing holes for the rotary elements need be machined, whereas the holes 20 may remain unmachined.

To permit the accommodation of a large number of springs within a circle of a small diameter, two or more concentric rows of preferably staggered holes 20 may be provided on the discs 19. Fig. 9 shows, for instance, a portion of a disc- 19 with two concentric circles of staggered holes.

The tool 8 may be detached from the tiller shaft by removing the pin 22, without the necessity of loosening or removing at the same time the torsion spring pertaining thereto.

.The passage of the bar springs through'the bearing discs located between the tool and the abutment pertaining thereto, as shown in Fig. 7 is also possible in the arrangement illustrated in Fig. 6. In that case the bearing disc-12 must be provided with one or more circles of concentrically located holes similar to the manner shown in Fi 9. When in the hitherto described modification the tools 8 are operated the springs are only subject to a torsional strain. In order to attain the necessary spring action of the tool with the forces acting on the tool, the length of the spring must not be below acertain minimum value. For this reason the springs in Fig. 7 which belong to the tools located at the right hand sideof the center are passed across to and fixed in the left hand abutment, and the tools located at the left hand side are fixed in the right hand abutment. The crosssections of the springs of different length may be so designed, that equal forces acting on the various springs cause approximately equal angles of defiection'of the tools.

As Figs. 2 to 9 show the springs do not extend beyond the diameter of the bearing discs. The disturbing diameter of the working mechanism is thus in tillers, resiliently supported according to the present invention, considerably smaller than in the hitherto known designs with coiled springs, in which the necessary loops of the springs are located much farther outside, and have the inherent disadvantages pointed out at the beginning. At the same time the danger of the breaking of the springs is eliminated, which occurs with coiled springs, when the coils encounter rigid obstacles.

Since the torsion bars, as pointed out before, must not be shorter than a certain minimum, to maintain a certain amount of resiliency, it would be very difficult in the modifications, so far described to drive the tiller shaft from the center, because insuch a case the length of the springs could not be greater than the distance from the middle of the driving shaft to its ends. This distance is in small tillers frequently too small to obtain suflicient resiliency of the tools. This disadvantage is avoided by not mounting the tools directly on the springs or on the rotary elements such as 21 connected with the springs, but on tubes, which surround the torsional springs.

Such a construction is illustrated in Fig. 10 of the drawings. Referring to this figure, it will be seen that on the tiller shaft 1, driven at the middle of its length by the gearing 30, is mounted a supporting disc 31. To each end of the shaft is fixed an abutment which consists of a disc 32, the cover 33 and the holding nut 134. The disc 32 has a milled recess 133 and a bore 39 for each spring bar 3, through which these springs with their surrounding tubes 34 can be inserted and removed. A U-shaped liner 135 safeguards each tube 34 against displacement in an axial direction. The bent over ends of the springs 3 at the left hand side engage respective recesses 133 provided in disc 32, so that the springs 3 are thus anchored to the disc 32. The bent over right-hand end of each spring engages a corresponding milled recess of its tube 34 and thus rigidly connects tube and spring at this point. It will be understood, that this connection may be effected in any other suitable manner, for instance by means of pins. Each tube 34 is freely rotatably journaled in the discs 31 and 32 in bushings 36 and 37 respectively. The tool Sis fixed by a pin 137 in a socket 38 which in turn is fixed to tube 34.

The resistance moments of the tube and the torsion rod pertaining to it may be chosen in different relation to each other. If the tube is quite rigid compared with the rod, the effective length of torsion has no relation to the point of the tube at which the tool 8 is attached. In this way the result is attained, that the lengths of the rods may be made equal for all tools of the machine. If, however, the tube is also made elastic the total elastic length of the device is composed of the length of the torsion rod measured from its lefthand to its right-hand end, and of the length of the elastic tube 34 measured from its righthand end up to the tool. The effective length of the spring is thus considerably increased in this design. In this way it is possible to utilize the space to greater advantage, particularly in the case of comparatively small ro tary members, and to accommodate the necessary s rings in a more convenient manner. The tu e might be less rigid than the torsion spring, so that a smoother spring action results than could be obtained with the torsion spring alone. The engagement of the tool with the soil then commences comparatively gently. With long springs it is preferable to construct the tube with a higher resistance moment than the torsion bar, so that the bar contained Within the comparatively rigid outer tube is efliciently protected against undesired bending strains. In this case the bars are practically pure torsion springs.

On one tube 34 may be mounted a pluralityof tools 8. The tools are then preferably circumferentially displaced in relation to one another, so that their points enter the ground such a manner, that the openings come in line with the milled recesses 133 of the disc 32, so that after removal of the U-shaped liners 135 all the springs and tubes may be removed from or inserted into the apparatus simultaneously. It will be understood that special bearing discs, as described above, may be provided and that the ends of the springs may have any of the shapes hereinbefore mentioned.

Fig. 11 of the drawings shows a further modification of In invention, which differs from those described before by the tool 8 being adapted to rock around an axis located outside of the axis of the spring 3. In the design illustrated in this figure there is mounted on the rotary shaft 1 a square spring 3 attached at the left-hand end, in the manner already described. On a supporting disc 40, through whichthe spring 3 passes freely, is pivoted the tool 8 by means of a pivot socket 41. This socket 41 has an extension 42, which engages an abutment 43 rigidly connected with the spring 3. If the tool 8 is turned with its point towards the observer, the extension 42 of the socket 41 presses against the stop 43 of the spring 3 and thus transmits the rotation of the tool to the spring.

By means of this arrangement the springs may be moved still closer to the rotary shaft. The device for transmitting the rotary movement of the tool to the spring may be so dimensioned, that any desired ratio of transmission results, for instance, so that only a small torsion of the spring occurs for a large deflection of the tool. Furthermore, as shown in Fig. 11, the supporting disc 40 serves at the same time for supporting the spring 3 against transverse bending strains in case the spring 3, as illustrated in Figs. 7 and 11 extends beyond the supporting disc 40 to a more remote tool.

The provision of a transmitting or entraining device between tool and torsion bar permits the mounting of the torsion bars in any desired direction with respect to the rotating shaft. Fig. 12 of the drawings shows an arrangement in which the torsion bars are arranged at right angles to the rotating shaft 1. As in Fig. 11 the tools are pivotally attached to a special supporting disc 40 by means of a pivotal socket 41, which engages with its detent 43 and abutment pin 143 connected with the torsion bar 3. This bar is in this case diametrically disposed in a disc 44 tools 8 recede behind this disc when encountering rigid obstacles, whereby the tools are further guarded against destruction.

The use of the described gearing between the tools and the spning bars renders it furthermore possible to a ply my invention also to tools, which are ab e to give away in circumferential direction only and have thus a constant working de th. Such an arrangement is illustrated in igs. 13 and 14 in two views at right angles to each other.

In this modification a hub 47 carrying two rigidly attached tools 8 is rotatably mounted on the driving shaft 1. The torsion bar for these tools is diametrically mounted in an oval disc 48 in the manner shown in Fig. 12. The largest diameter of oval disc 48 is at least as great as that of the circle described by the points of the tools. On hub 47 is pro vided a detent 150 which, when the tools encounter the soil, engages an abutment 151 fixed on torsion bar 3, and they recede concentrically to the driving shaft 1 when encountering rigid obstacles, until they pass behind their disc 48 and are then protected against breakage by the solid discs. These discs 48 are of such stron construction, that they raise the entire tail 0 the machine when encountering rigid obstacles and thus safeguard the tools against breaka e.

Intermediate gearing of any ind between tool and spring bar, and supporting discs as guards behind which the tools are able, to recede, may also be emplo ed in the other modifications described be ore. In Fig. 15 of the drawings is shown, for instance, an arrangement, which combines the advantages of the designs according to Fi s. 10, 11 and 12. The general arrangement sIiown in Fig. 15 corresponds in its design substantially with that shown in Fig. 10. Like parts in these two figures are therefore indicated by like letters of reference. The bar spring 3 {is here of square cross-section, without any special deformation of the ends of the spring. The proper length of the bar may thus simply be cutoff the stock and be annealed and tempered. The tube 34 surrounding the spring has at its right -hand end a square bore into which the end of the spring is inserted. The tube is at both ends freely rotatably journaled in bushings 36 and 37. The left-hand end of the spring is fixed in supporting disc 32 in a bushing 38 which prevents this end from rotating. The tool 8 is mounted on a pivotal socket 41 located outside the spring arrangement and pivotally attached to disc 32. As in Fig. 11 the tool socket 41 engages with its detent 42 the abutment 43 fixed on tube 34 in themanner described with reference to Fig. 11. Supporting disc 32 is adapted to serve at the same time as a guard disc through the peripheral extension 49. This extension may be de tachably mounted on supporting disc 32 as shown.

In this arrangement also a plurality of tools may operate in conjunction "with a single spring. There is, for instance, in the center of the arrangement shown in broken lines a second supporting disc with a tool, which is likewise connected with the tube in the manner just described.

These supporting discs, which are located bet-ween the center driving gear 30 of shaft 1 and either end of this shaft, may, as shown in Figs. 7 and 9, be provided with concentric rows of holes through which the tubes of the other tools can freely pass. It will be understood that my invention may be applied to various sizes and patterns of machines for tilling or cultivating soil.

Various modifications and changes may be made without departing from the spirit and the scope of the invention, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

I claim as my invention 1. A rotary tiller, comprising a driven shaft, torsion spring bars mounted on said.

is)haft and tools connected with said torsion ars.

2. A rotary tiller, comprising a driven shaft, torsion springs in the form of long bars, means for rigidly connecting said bars at least at one end with said shaft, and tools connected with said bars at points removed from their rigid ends.

A rotary tiller, comprising a driven shaft, a plurality of torsion springs, each fixed at least at one of its ends to said shaft and having its fixed end of polygonal crosssection, and tools connected with said torsion springs.

4. A rotary tiller, comprising a driven shaft, torsion spring bars fixed on said rotary member and having polygonal cross-section along their entire length, and tools connected with said torsion springs.

5. A rotary tiller, comprising a driven shaft, bar-shaped springs mounted on and in parallel to said shaft, and tools connected with said springs.

6. A rotary tiller, comprising a driven rotary member, bar torsion springs fixed at one end to said rotary member, a surrounding tube for each spring fixed at one of its ends to the free end of the spring, and tools connected with said tubes.

7. A rotary tiller, comprising a driven rotary member, bar-shaped torsion springs of polygonal cross-section, fixed at one end to said rotary member, a surrounding tube for each spring having a corresponding polygonal socket in one of its ends to receive and hold the free end of the spring, and tools connected with said tubes.

8. A rotary tiller, comprising a driven rotary member, bar torsion springs fixed at one r end to said rotary member, and a surrounding tube for each spring, having one of its ends fixed to the free spring end, the moment of resistance of the tube being different from the moment of resistance of its enclosed spring.

9. A rotary tiller, comprising a driven rotary member, bar torsion springs fixed at one end in said rotary member, and a surrounding tube for each spring, having one of its ends fixed to the free spring end, said tube having a greater moment of resistance than its enclosed spring.

10. ,A rotary tiller, comprising a driven shaft, torsion springs disposed substantially parallel to the axis of said shaft, supporting elements rigidly connected with said-shaft and adapted to support said springs and tools connected with said springs.

11. A rotary tiller, comprising a rotary element including a driven shaft, torsion bar springs disposed substantially parallel to the axis of said shaft and being fixed at least at one of their ends to said rotary element, a supporting disc fixed upon said shaft intermediate its ends and being provided with holes through which said springs pass, and which form a support against lateral deflection of said springs, and tools connected with said springs.

12. A rotary tiller, comprising a rotary element including a driven shaft, torsion springs disposed substantially parallel to the axis of said shaft, and being fixed at one of their ends to said rotary element, a surrounding tube for each spring having one of its ends fixed to the free end of its spring, and bearings rigidly connected with said shaft for rotatably supporting both ends of each tube, and tools connected with said tubes.

13. A rotary tiller, comprising a driven shaft, torsion bar springs disposed in parallel to the shaft axis and a supporting element for said springs consisting of a disc fixed on said shaft and having transverse recesses adapted to permit the lateral insertion of said springs and to hold the spring end against rotation on its axis, and of a cap covering the outside and the periphery of said disc for holding the springs inserted into their recesses in position, and tools connected with said springs.

14. A rotary tiller, comprising a driven shaft, torsion bar springs disposed in parallel to the shaft axis and a supporting element for said springs consisting of a disc fixed on said shaft and having transverse recesses adapted to permit the lateral insertion of said springs and to hold the spring end against rotation on its axis, and of a cap covering the outside and the periphery of said disc for holding the springs inserted into their recesses in position, and tools connected with said springs, said cap being rotatable on said disc and being provided with transverse holes registerable with said disc recesses when the cap is turned into the proper position to permit the insertion and removal of said springs.

guards behind which the tools recede when said torsion springs are put under tension by 15. A rotary tiller, comprising a driven the tools.

shaft, bar-shaped torsion springs and a surrounding tube for each spring, fixed at one of its ends to one end of its spring, a disc fixed at one of the shaft ends and containing a socket element for each spring adapted to hold the other spring end in fixed position in said disc, said disc also having a bearing for each tube for rotatably supporting the free enld of each tube and tools connected with said tu es.

16. A rotary tiller, comprising a driven shaft, torsion bar springs disposed around the shaft in parallel to its axis, means on said shaft for fixing each spring at one of its ends to prevent its rotation on its own axis, means on said shaft for freely supporting the other end of each spring and tools connected with said springs.

17. A rotary tiller, comprising a shaft driven from a point about midway its ends, torsion bar springs disposed around said shaft in parallel to its axis and extending respectively across the entire available lengths of the shaft halves, means on said shaft for fixing each spring at one of its ends to prevent its rotation on its own axis, means on said shaft for freely supporting the other end of each spring, discs mounted on said shaft intermediate the spring ends provided with holes in which said springs are supported against lateral deflection, and tools connected with saidsprings.

18. A rotary tiller, comprising a rotary member, torsion springs mounted on said rotary member, tools pivotally mounted on said rotary member, and a mechanism for transmitting the pivotal motion from said tools to said spring.

19. A rotary tiller, comprising a rotary member, torsion springs mounted on said rotary member, tool holders containing tools and being pivotally mounted on said tools, said rotary member outside of its axis of rotation, and a mechanism for transmitting the pivotal motion from said holders to said springs.

20. A rotary tiller, comprising a rotary member, torsion springs mounted on said rotary member, a tool holder for each spring containing a tool and being pivotally mounted on said rotary member outside ofthe longitudinal axis of said springs, a detent on each holder, and an abutment for each detent fixed to the pertaining torsion spring for transmitting the pivotal motion from the tools to their pertaining spring.

21. A rotary tiller, comprising a driven rotary member, torsion springs mounted on said member, tools operatively connected with said torsion springs, and discs mounted upon said rotary member adjacent to said tools, said discs having extensions acting as In testimony whereof I afiix my signature.

GEORG PENEFF. 

